面向梯度温度场的钛合金盘坯加热试验研究

Experimental research on heating process of titanium alloy disc-type billet aiming at gradient temperature field

面向梯度温度场设计了局部热保护的钛合金盘坯缩比件加热实验方案,并通过试样边缘、过渡区和中心的温差确定温度梯度的变化。对比研究了到温加热与随炉加热两种加热方式,发现到温加热方式可获得更明显的温度梯度。此外,分析了影响钛合金盘坯温度梯度分布的显著工艺参数。当几何因素一定即试样的尺寸和形状不变时,到温加热温度对试样边缘和中心的温差有着显著影响,到温加热温度越高,温度梯度越明显。发现试样尺寸越大,试样温度梯度越大。随着换热面积增大、环境温度升高和环境与试样温差的增大,对流换热系数减小。

Aiming at a gradient temperature field,a heating experimental scheme with local thermal protection for a scaled titanium alloy disc-type billet was designed,and the change of temperature gradient was determined by the temperature difference between the edge,the transition zone and the center of the sample. The two heating approaches,namely discordant heating and synchronous heating were compared. It is found that the approach of discordant heating can obtain a more obvious temperature gradient. Furthermore,the significant process parameters affecting temperature gradient distribution of titanium alloy disc-type billet were analyzed. When the geometric factors are certain,that is,the size and shape of the sample remain unchanged,the discordant heating temperature has a significant influence on the temperature difference between the edge and the center of the sample. The higher the discordant heating temperature is,the more obvious the temperature gradient is. It is found that the larger the sample size is,the larger the temperature gradient is;the increase of heat transfer area and furnace temperature results in the increase of the temperature difference between the furnace and the disc-type sample,then leads to the decrease of the heat transfer coefficient.